WO2003016039A1

WO2003016039A1 - Continuous flocked extrudate and process for its production

Info

Publication number: WO2003016039A1
Application number: PCT/US2002/025645
Authority: WO
Inventors: Linwood E. Wade
Original assignee: Wade Linwood E
Priority date: 2001-08-10
Filing date: 2002-08-12
Publication date: 2003-02-27

Abstract

A process is provided for preparing a flocked tape (12 and 12') having a base film side and a flocked side with a usable splice. The ends of two sections of flocked tape are cut along a diagonal. The two cut ends of flocked tape are abutted along a common diagonal cut line. Then, the base film side of the flocked tape is contacted at the cut line with a heat-sealable, reinforced tape. Then, heat and pressure are applied to form the heat seal. In another aspect, a process is provided for preparing a continuous flocked extrudate for use as window wiping seals, comprising: preparing a spliced flocked tape according to the process above, continuously extruding a resin, and contacting the resin while hot with the spliced flocked tape.

Description

DESCRIPTION

CONTINUOUS FLOCKED EXTRUDATE AND PROCESS FOR ITS PRODUCTION

Background of The Invention

The invention relates to an improved flocked material suitable for preparing continuous flocked extrudates for use as window wiping seals or the like for automotive and other vehicle uses.

Automobiles and other mobile units typically include windows that can be raised and lowered. These windows are generally held within frames having a seal designed to wipe the window as they are moved from a closed, exposed position to one internal of a door body or the like. The wiping edge is typically dressed with a flocking (velvet-like material) to enable the wiping edge to ride smoothly over the surface of the window and wipe it as it is drawn against the wiping edge.

One established method for manufacturing the combined seal/wiper involves extruding a base member comprised of a polymeric material, often also including a metal structural section, and applying a flock in the form of a plastic substrate having flocking adhered to it. Sheets of this flocked substrate are typically cut into narrow strips, often called flocked tapes, and rolled onto spools of a size convenient for shipping and handling. Typical spools can hold up to a thousand yards or more, e.g., 2500 yards in some cases. These spools contain splices each of which causes a length of the extruded part to be scrapped. When attaching a tape of this type to an extruded base member, the tape is preferably fed into contact with the extruded base member within the extruder die used to form the base member or suitably after the extruder die. Because an extruder of the type used to produce a combined seal/wiper operates continuously to shape the polymeric material into the desired cross section, it would be desirable for the tape to be continuous also. Unfortunately, this has not been possible as a practical matter due to the finite length and materials of manufacture. The presence of splices will not only cause unsightly and dysfunctional parts — unacceptable to the automobile manufacturers and consumers alike — it can also affect the operation of an extruder, which is intended to operate on a continuous basis.

One current practice is to clearly identify the splices by using a metallic splicing tape that can be detected by automated equipment. The part containing the spice is then discarded. This can result in considerable losses of product. In some cases, the combined seal/wiper can have two or more flocked surfaces. In these cases, the losses are multiplied.

It would be desirable to provide alternative processing techniques for preparing parts of this type with a high degree of reliability. There remains a need for simple and efficient means to provide a spliced flocked tape which can be efficiently processed with minimal waste.

Brief Description of the Drawings

The invention will be better understood and its advantages will become more apparent from the following description, especially when read in light of the accompanying drawings, wherein:

Figure 1 is a schematic, cross-sectional view of a molded combined seal/wiper having two flocked wiping surfaces according to the invention;

Figure 2 is a schematic side elevation of a typical extrusion process for forming a combined seal/wiper of the type shown in Figure 1;

Figures 3-5 are foreshortened top plan views illustrating the steps involved in forming the splice of the invention; and Figures 6-9 are schematic cross sectional views of several embodiments of splicing tapes employed according to the invention.

Summary of the Invention

It is another object of the invention to provide a spliced flocked tape suitable for use in preparation of a molded combined seal/wiper having at least one flocked wiping surface.

It is an object of the invention to provide a simple and effective method for preparing a molded combined seal/wiper having at least one flocked wiping surface employing a spliced flocked tape of the invention.

It is another object of the invention to provide alternative processing techniques for preparing a molded combined seal/wiper having at least one flocked wiping surface of this type with a high degree of reliability.

It is another object of the invention to provide an improved process for providing simple and efficient processing to produce a molded combined seal/wiper having at least one flocked wiping surface by providing a method of producing a useable splice in flocked tape.

It is yet another object of the invention to provide an improved process for applying a flocked wiping surface to a molded combined seal/wiper.

These and other objects are accomplished by the invention, which provides an improved process for preparing a molded combined seal/wiper having at least one flocked wiping surface.

In one of its aspects the invention provides a process for preparing a flocked tape having a base film side and a flocked side with a usable splice comprising: cutting the ends of two sections of flocked tape along a diagonal; abutting the two cut ends of flocked tape along a common diagonal cut line; contacting base film side of the flocked tape at the cut line with a heat-sealable, reinforced tape; and applying heat and pressure to the heat-sealable, reinforced tape sufficient in time and degree to form a secure splice.

In another aspect the invention provides a spliced flocked tape prepared according to the process above.

In yet another aspect, the invention provides a process for preparing a continuous flocked extrudate for use as window wiping seals, comprising: preparing a spliced flocked tape according to the process above; continuously extruding a resin; and contacting the resin while hot with the spliced flocked tape.

The processes and the materials produced have a number of preferred aspects, which are described below and shown in the attached drawings.

Detailed Description of The Invention

While the invention has broader utility, the following description will detail preferred forms wherein a combined seal/wiper having at least one flocked wiping surface is prepared. The drawings illustrate a number of variations, each with its particular advantages.

As used herein, the term "flocked extrudate" is meant to include contoured members made of one or more plastic materials, some with embedded metal reinforcements, designed to be fixed to an opening in a door or other vehicle part, which can be used to guide and/or support a window or other moveable member.

The term "flocked tape" is meant to include tapes such as those offered by Dorrie International of Norwalk, CT under the trade designations 80 Black Flock™ made of black polyester fiber flock bonded to a black PVC (polyvinyl chloride) film and 50 Black Flock™ made of black polyester fiber flock bonded to a black polyolefin film. The PVC backed material is useful for adhering in an extruder to PVC and its elastomers, such as those sold under the Alcryn® and Sunprene® trademarks. The 50 Black Flock™ will adhere well to EPDM (ethylene propylene terpolymer) rubber, TPO's (thermoplastic olefin elastomers), TPE's (thermoplastic elastomers), TPV and polybutadiene. An important feature of the invention is that, regardless of the material of the flocked tape, it can be fed in a continuous manner to produce a flocked extrudate.

Figure 1 is a schematic, cross-sectional view of a flocked extrudate 10 of the invention including two areas with spliced flocked tape material 12 and 12' formed in accord with the invention. The flocked extrudate is comprised of a flocked tape material 12 and 12' affixed to a molded structural member 14. The specific shape of structure 14 will be determined by the particular application intended and will complement the particular structure to which it will be attached. Various flanges and the like can provided for attachment, cushioning and/or decoration. The extrudate may also include an internal structural metal member 16, which is typically included for added strength and shape retention.

The flocked tape is attached to an extrusion profile by contact therewith at the face of an extrusion-forming die or immediately adjacent to the die exit in the case of thermoplastic extrusion materials. Alternatively, contact can be made at the exit of a curing tunnel following extrusion of the profile in the case of thermosetting resins such as EPDM, or the like.

A representative process for forming the flocked extrudate is shown schematically in Figure 2. There a flocked tape 12 is fed to the exit end of an extruder 18, fed with resin from a hopper 20 and a metal reinforcement 16. The back side of the flocked tape is contacted with the resin while hot to secure it to the extruded resin. The invention enables running the process continuously by eliminating costly stops and minimizing waste through the use of a useable splice. The resin will typically be a member selected from the group consisting of TPO, TPE, EPDM, TPV and PVC. Figures 3-5 are foreshortened top plan views illustrating the steps involved in forming the splice of the invention. The flocked tape 12 (and 1 12) has a base film side (back side) shown up here and a flocked side, which is on the other side and not shown. Figure 3 shows ends of the two flocked tape sections 12 and 1 12 being overlapped. In this position they are cut along a diagonal, preferably at an angle α of at least 45° to a line normal to the length of the tape, and typically 60° tp 75°.

Figure 4 illustrates the process following cutting wherein the two cut ends of flocked tape are abutted along a common diagonal cut line. The base film side of the flocked tape is contacted at the cut line with a heat-sealable, reinforced tape. The reinforced tape is overlapped with the base film to an extent sufficient to provide a strong seal, e.g., at least about 10% of the length of the splice. Then, the excess material extending beyond the edges of the flocked tape are cut off.

Figure 5 shows the tape after trimming and heat and pressure are applied to form the heat seal.

Figures 6-9 are schematic cross sectional views of several embodiments of splicing tapes employed according to the invention. The splicing tape of the invention is heat sealable, yet study enough to be contacted with hot extruded resin. Preferably it will retain its dimensional integrity at temperatures of at least 300°F and preferably of at least about 350°F. thus, we refer to it as a reinforced tape. In each of its illustrated forms it will comprise a layer of a resin compatible with the base film of the flocked tape and a layer having a melting point above that employed during heat sealing. One preferred reinforcing layer is polyethylene terephthalate, but other materials such as polyurethane and nylon can be employed. The thickness of the reinforcing layer should be sufficient to provide the desired strength, but not so thick that it affects the appearance or function of the part being made or the operation of the extruder. Typical thicknesses are within the range of 0.5 to 1.0 mils. The nature of the compatible resin depends on the base film, which in turn depends on the extruded resin. Figure 6 shows a one mil polyurethane coat 120 over a 4 mil layer of PVC 122. Figure 7 shows outer layers of PVC adhered by layers 124 and 124' to a reinforcing layer of a suitable polyester such as 0.5 mil polyethylene terephthalate. These two illustrations are suitable for use with base films of PVC and are particularly suitable for use with extruded PVC resins.

Figure 8 shows outer layers of polyolefin 126 and 126' adhered by layers 124 and 124' to a reinforcing layer of a suitable polyester such as 0.5 mil polyethylene terephthalate. Figure 9 is similar, but shows a layer of cross-linked polyolefin 130 in place of the polyester and does not employ an adhesive. These two illustrations are suitable for use with base films of polyolefin, especially suitable for use with an extruded resin that is a member selected from the group consisting of TPO, TPE, EPDM and TPV.

The above description is intended to enable the person skilled in the art to practice the invention. It is not intended to detail all of the possible modifications and variations which will become apparent to the skilled worker upon reading the description. It is intended, however, that all such modifications and variations be included within the scope of the invention which is seen in the above description and otherwise defined by the following claims. The claims are meant to cover the indicated elements and steps in any arrangement or sequence which is effective to meet the objectives intended for the invention, unless the context specifically indicates the contrary.

Claims

1. A process for preparing a flocked tape having a base film side and a flocked side with a usable splice comprising: , cutting the ends of two sections of flocked tape along a diagonal; abutting the two cut ends of flocked tape along a common diagonal cut line; contacting base film side of the flocked tape at the cut line with a heat-sealable, reinforced tape; and applying heat and pressure to the heat-sealable, reinforced tape sufficient in time and degree to form a secure splice.

2. A process according to claim 1 wherein the reinforced tape is trimmed to the dimensions of the flocked tape following heat sealing.

3. A process according to claim 1 wherein the flocked tape ends are cut at a diagonal angle of at least 45° from a line transverse to the length of the tape.

4. A process according to claim 3 wherein the angle is within the range of from about 60° to 75°.

5. A process according to claim 1 wherein the heat sealable, reinforced tape comprises a layer of a resin compatible with the base film and a layer having a melting point above that employed during heat sealing.

6. A process according to claim 1 wherein the heat sealable, reinforced tape comprises a layer of polyvinyl chloride and a layer of polyurethane.

7. A process according to claim 1 wherein the heat sealable, reinforced tape comprises a layer of a polyolefin and a layer of polyethylene terephtalate.

8. A process according to claim 1 wherein the heat sealable, reinforced tape comprises two outer layers of polyolefin and an internal reinforcing layer of polyethylene terephtalate.

9. A process according to claim 1 wherein the heat sealable, reinforced tape comprises two outer layers of polyvinyl chloride and an internal reinforcing layer of polyethylene terephtalate.

10. A process according to claim 9 wherein the layers are secured with an adhesive.

11. A spliced flocked tape prepared according to the process of claim 1.

12. A process for preparing a continuous flocked extrudate for use as window wiping seals, comprising: preparing a spliced flocked tape according to the process of claim 1; continuously extruding a resin; and contacting the resin while hot with the spliced flocked tape.

13. A process according to claim 12 wherein the flocked tape ends are cut at a diagonal angle of at least 45° from a line transverse to the length of the tape.

14. A process according to claim 13 wherein the angle is within the range of from about 60° to 75°.

15. A process according to claim 12 wherein the heat sealable, reinforced tape comprises a layer of a resin compatible with the base film and a layer having a melting point above that employed during heat sealing.

16. A process according to claim 15 wherein the resin is a member selected from the group consisting of TPO, TPE, EPDM, TPV and PVC.

17. A process according to claim 16 wherein the resin is a member selected from the group consisting of TPO, TPE, EPDM and TPV, the base film of the flocked tape comprises a polyolefin and reinforced tape comprises a layer of a polyolefin and a layer of polyethylene terephtalate.

18. A process according to claim 16 wherein the resin PVC, the base film of the flocked tape comprises PVC and the reinforced tape comprises a layer of PVC and a layer of polyethylene terephtalate.

19. A product prepared according to the process of claim 12.

20. A process for preparing a continuous flocked extrudate for use as window wiping seals, comprising: preparing a spliced flocked tape by cutting the ends of two sections of flocked tape along a diagonal, abutting the two cut ends of flocked tape along a common diagonal cut line at an angle of at least 45° from a line transverse to the length of the tape, contacting base film side of the flocked tape at the cut line with a heat-sealable, reinforced tape, and applying heat and pressure to the heat-sealable, reinforced tape sufficient in time and degree to form a secure splice; continuously extruding a resin; and contacting the resin while hot with the side of the spliced flocked tape having the reinforced tape thereon.